The terms “VDR” or “visual dynamic range” and “EDR” or “enhanced dynamic range” as used herein may refer to a dynamic range (e.g., 10,000 nits, 12,000+ nits, etc.) wider than a relatively low dynamic range such as a standard dynamic range (SDR), an intermediate high dynamic range (e.g., 1000 nits, 2000 nits, etc.), etc., and may include, but is not limited to, a wide dynamic range up to the instantaneously perceivable dynamic range and color gamut which human vision can perceive at an instant.
Multiple layers may be used to deliver video data from an upstream device such as a multi-layer video encoder to downstream devices. For example, visual dynamic range (VDR) video data can be carried in the combination of a base layer and an enhancement layer (EL) of the multiple layers for viewing experience of VDR displays. BL image data may be encoded with low or partial dynamic range (e.g., SDR, an intermediate high dynamic range, etc.) image data derived from VDR images. EL image data may be encoded with residual image data which, along with image data inversely mapped from the BL image data enables a downstream recipient system to reconstruct a version of the VDR images.
The parameters to be used for inverse mapping by a downstream recipient system can take a significant portion (e.g., 20%, 30%, 50% or more, etc.) of an overall bit rate used to stream a corresponding media program. In some instances, transmission of these parameters may need a bit rate around 50 kbps˜100 kbps, no matter what image resolutions with which the media program is being streamed or transmitted. This overhead in the overall bit rate becomes worse for partition-based prediction or inverse mapping operations, as the overhead may be proportional to the number of partitions in each of individual image frames. At the very low bit rate for relatively low resolution video streaming (e.g., <1 Mbps, a resolution of 640×340 at 800 kbps, a resolution of 384×216 at 150 kbps, etc.), the overhead is very significant (e.g., >50%, etc.).
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. Similarly, issues identified with respect to one or more approaches should not assume to have been recognized in any prior art on the basis of this section, unless otherwise indicated.